Performance of Autonomous Control

ABSTRACT

In various example embodiments, a system and method for determining a total weight of a vehicle, transmitting the total weight measured to the vehicle&#39;s autonomous control system, and controlling the vehicle according to the total weight of the vehicle. The system and method further transmits information between separate vehicles with similar autonomous control systems. A method includes: providing predetermined calibration settings relating drive force to motor speed for a vehicle travelling at various speeds, determining that one or more vehicle performance parameters fall within a threshold range, determining the vehicle&#39;s longitudinal acceleration and drive force, determining a total weight comprising a weight of the vehicle and a weight being hauled by the vehicle; transmitting the total weight to the autonomous control system, and controlling the vehicle according to total weight of the vehicle.

BACKGROUND Field of the Invention

This invention generally relates to transportation and more particularlyrelates to autonomously controlled vehicles.

Background of the Invention

Many factors affect electric, gas, and hybrid vehicle control.Autonomous driving features, such as cruise control, adaptive cruise(radar following), automatic braking, and self-driving need to controlacceleration, deceleration, and steering. Typical feedback controlsystems are used to maintain control of braking, steering, andacceleration within expected system variation. Vehicles that have largeweight changes are difficult to control properly with feedback control.These weight fluctuations may occur for a variety of reasons. Forexample, often the amount of goods or other items being hauled may varyfrom 100 kilograms or less, to many tons. The amount of goods or otheritems being hauled or placed in the vehicle may have a significanteffect on how the vehicle performs. For example, hauling heavy loads mayresult in greater difficulty operating efficiently, accelerating,braking, or steering.

Tuning the gains of the PID controllers is specific to a range ofvehicle weights that is typically narrower than the capability of thevehicle. Vehicle weight affects braking distance and acceleration whichcan be critical for vehicle owners and adaptive cruise, cruise, andself-driving vehicles. For semi-autonomous vehicles, there is no knownmethod of informing the systems of an adjusted weight of the vehicle.Vehicle weight may fluctuate frequently based on number of passengers inthe car, loading the vehicle with any good or substance, attaching atrailer, or towing another item. Misinformation about the weight of thevehicle may cause feedback control systems to misjudge the vehicle'sability to maneuver which may result in losing control of the vehicle,crashing, or causing injury to the passengers or others.

Semi-autonomous and autonomous cars use a variety of systems to gaugetheir surroundings and their environment. Techniques and methods such asradar, lidar, GPS, odometry, optical cameras, and computer vision allowthe vehicles to operate without human input. While these systems areadept in measuring where in space the vehicle is, they do not calculatehow much the vehicle weighs.

Without a method of measuring the weight of a vehicle and feeding theinput to the autonomous control system (ACS) the vehicle will manage theacceleration, braking, and steering less efficiently. Therefore, amethod is needed for measuring the weight of the vehicle andtransmitting the information to the autonomous control system.

SUMMARY

This invention has been developed in response to the present state ofthe art and, in particular, in response to the problems and needs in theart that have not yet been fully solved by currently available systemsand methods. Features and advantages of different embodiments of theinvention will become more fully apparent from the following descriptionand appended claims, or may be learned by practice of the invention asset forth hereinafter.

Consistent with the foregoing, a system and method for determining theweight (mass) of a vehicle and transmitting the information to anautonomous control system, including transmitting information betweenvehicles with similar autonomous control systems are disclosed. A methodincludes: providing predetermined calibration settings relating enginedrive force to engine speed and electric motor drive force to motorspeed for a vehicle travelling at various speeds, altering accelerometerdata based on filtered vehicle pitch and roll data, determining that oneor more vehicle performance parameters fall within a threshold range,storing a plurality of data pairs that include longitudinal accelerationand drive force, and determining a slope of a line that linearlyapproximates the plurality of data pairs, the slope indicating a totalweight, the total weight comprising a weight of the vehicle and a weightbeing hauled by the vehicle; transmitting the total weight to theautonomous control system, and controlling the vehicle according tototal weight of the vehicle. The total weight of a vehicle, the driveforce and speed of the vehicle comprising velocity and acceleration mustbe known in order to do the required calculations. The system and methodcan then determine a feed forward parameter of the total weight anddelta pitch; transmitting the feed forward parameter to the vehicle'sautonomous control system; and controlling the vehicle according torevised parameters incorporating the feed forward parameter.

The autonomous control system of the vehicle includes the weight of thevehicle in all calculations and control of the vehicle. Since the weightof the vehicle changes over time, the autonomous control system activelymonitors the weight of the vehicle and enhances the controls toincorporate the necessary controls based on weight. In addition to theweight information for the vehicle, the system also receives informationfrom similar autonomous control systems in separate vehicles. The weightof these separate vehicles influences the separate vehicle's behaviorbased on the separate vehicle's weight and the road conditions. Thisdata regarding weight and the separate vehicle's interface with roadconditions based on weight informs the vehicle's autonomous controlsystem, modifying the response characteristics, and improving thecontrol of the vehicle.

To calculate the drive force of the electric powertrain, the motorcurrent, voltage, and motor speed, must be known to determine thetorque. This torque may be used to calculate a drive force. Drive forceand longitudinal acceleration may be used to calculate mass. In hybridpowertrains, such as the powersplit IVT, or eCVT (Prius, Fusion), themotor torques may be used to sense the engine torque, such that thetotal torque delivered by the electric powertrain may be calculated.This total torque of all contributing electric motor components may thenbe used together with the torques from other power delivery systemcomponents including internal combustion engine drive forces todetermine a total combined drive force. Drive force is the portion ofthe force generated by the drive wheels that accelerates the mass of avehicle. Any friction, air drag, etc. present is not part of the driveforce. During calibration, the system calculates this force by measuringthe mass of the vehicle, and the acceleration. These values are thenused to determine force F=m*a.

For hybrid vehicles, there are many drive forces that are combined todeliver a combined drive force. These comprise both positive andnegative drive forces. Positive drive forces include internal combustionengines, electric motors, and other mechanical forces that contribute tothe motive force driving the vehicle in the desired direction of travel.Negative drive forces comprise forces that diminish the motive forcedriving the vehicle in the desired direction. For example, brakes arenegative drive forces when they are applied to slow the speed of thevehicle. Electric motors can be used to slow down or brake the speed ofa vehicle when operating as generators or alternators to charge thebatteries or energy storage devices. While acting as generators,electric motors are contributing a negative drive force. The combineddrive force is the force delivered to the drive wheels that acceleratesthe mass of a vehicle.

In addition to drive forces, predetermined calibration settings relatingforce to motor or engine speed for a vehicle travelling at variousspeeds is also required. Accelerometer data may be altered based onfiltered vehicle pitch and roll data, determining that one or morevehicle performance parameters fall within a threshold range, storing aplurality of data pairs that include longitudinal acceleration and driveforce, and determining a slope of a line that linearly approximates theplurality of data pairs, the slope indicating a total weight, the totalweight comprising a weight of the vehicle and a weight being hauled bythe vehicle.

In certain embodiments, the method includes: providing predeterminedcalibration settings relating drive force to motor speed for a vehicletravelling at various speeds; providing accelerometer data to determinevehicle velocity, acceleration, and direction of travel; providingsensors sensing motor performance characteristics; providing vehiclepitch measurements, roll measurements or a combination thereof;determining filtered data based on the combination of pitch and rollmeasurements; providing accelerometer data to determine vehiclevelocity, acceleration and direction of travel; altering theaccelerometer data based on the filtered data; determining by use of oneor more processors, that one or more vehicle performance parameters fallwithin threshold ranges; determining a total weight of a vehicle andtrailer based on the predetermined calibration settings, accelerometerdata and the vehicle performance parameters being within thresholdranges; determining feed forward parameter of the total weight and deltapitch; transmitting the feed forward parameter to the vehicle'sautonomous control system; and controlling the vehicle according torevised parameters incorporating the feed forward parameter.

In another embodiment, the method further includes: storing, in responseto the vehicle performance parameters being within the threshold ranges,a plurality of data pairs, each data pair comprising a longitudinalacceleration and a drive force, the drive force determined according toa calibrated polynomial for a current velocity of the vehicle;determining a slope of a line that linearly approximates the pluralityof data pairs, the slope indicating a total weight, the total weightcomprising a weight of the vehicle and a trailer weight; wherein thedetermining the slope of the line comprises: setting the initial yintercept of force vs. acceleration to zero; and performing regressionanalysis on the plurality of data pairs resulting in a first order driveforce polynomial, a first order coefficient representing the totalweight.

In an embodiment, the drive force includes a combined drive force of allmotor drive forces, engine drive forces and motive force devices; andwherein providing predetermined calibration settings further consists ofrelating motor drive force to motor speed for the vehicle traveling atvarious speeds.

In a certain embodiment, the vehicle performance parameters are selectedfrom the group consisting of lateral acceleration, velocity, electricmotor speed, electric motor operating in braking mode as a generator,engine speed, longitudinal acceleration, brakes not being applied, and atransmission gear ratio.

In an embodiment, the method includes retrieving one or more of thevehicle performance parameters from a computing device for the vehicle.

In another embodiment, the combined drive force is determined bydetermining a polynomial for each integer velocity of the vehicle byperforming regression analysis on calibration data pairs for eachinteger velocity of the vehicle, the calibration data pairs comprising acalibration drive force, an electric motor speed and an engine speed,the calibration drive force determined by multiplying the weight of thevehicle with a longitudinal acceleration of the vehicle when the datapair was recorded.

In one embodiment, the motor is a motive force device comprising one ormore electric motors, internal combustion engines, and externalcombustion engines.

In some embodiments, the autonomous control system includes one or moreof the following: a semi-autonomous control system; a fully autonomouscontrol system; adaptive cruise; cruise control; self-driving; and lanecentering.

In an embodiment, the vehicle transmits information about the vehicle'sweight and response to road conditions based on the weight to one ormore separate vehicle's similar autonomous control system. In anotherembodiment, the vehicle receives information from the one or moreseparate vehicle's similar autonomous control system.

In a certain embodiment, the vehicle's autonomous control systemmodifies control of the vehicle according to revised parameters based onthe received information from the one or more separate vehicle's similarautonomous control systems. The modified control of the vehiclecomprises: controlling the braking of the vehicle; controlling thesteering of the vehicle; and controlling the acceleration of thevehicle.

In certain embodiments, a system includes: a vehicle comprising one ormore motors; one or more accelerometers that sense acceleration of thesystem; one or more processors; a drive force module that determines acombined drive force of one or more electric motors, engines and motiveforce devices; a vehicle pitch and roll module that determines filtereddata based on the vehicle pitch, roll or both, and alteringaccelerometer data based on the filtered data; an interface module thatretrieves one or more vehicle performance parameters; a performancemodule that determines whether the vehicle performance parameters fallwithin respective threshold ranges; a data module that stores, inresponse to the vehicle performance parameters being within therespective threshold ranges, a plurality of data pairs, each data paircomprising the longitudinal acceleration of the vehicle and a driveforce for the vehicle, the drive force determined according to acalibrated polynomial for a current velocity of the vehicle; a weightmodule that determines the weight being hauled by the vehicle bydetermining a slope of a line that linearly approximates the pluralityof data pairs, the slope of the line indicating a total weight, thetotal weight comprising a weight of the vehicle and a weight beinghauled by the vehicle; an output module that transmits the weight of thevehicle to the autonomous control system; an operation module thatmodifies operation instructions of the autonomous control system of thevehicle; and a control module that controls the vehicle based on themodified operation instructions.

In another embodiment, the system includes a detection module thatrecords and compares the combined drive force RPM to vehicle speed, anduses this ratio to determine the vehicle's axle ratio and tire size,which is then used to correct the calculated mass.

In an embodiment, the vehicle transmits information about the vehicle'sweight and response to road conditions to one or more separate vehicle'sautonomous control system; and the vehicle receives information from theone or more separate vehicle's autonomous control system and modifiescontrol of the vehicle according to revised parameters based on thereceived information from the one or more separate vehicle's autonomouscontrol systems.

In one embodiment, the modified control of the vehicle comprises:controlling the braking of the vehicle; controlling the steering of thevehicle; and controlling the acceleration of the vehicle.

In a certain embodiment, the system includes a calibration module thatdetermines a polynomial for each integer velocity of the vehicle byperforming regression analysis on calibration data pairs for eachinteger velocity of the vehicle, the calibration data pairs comprising acalibration drive force and an engine speed, the calibration drive forcedetermined by multiplying the weight of the vehicle with a longitudinalacceleration of the vehicle when the data pair was received, thelongitudinal acceleration including the force of gravity, the datamodule determining the drive force using the polynomial for a currentspeed of the vehicle.

In an embodiment, the one or more motors comprise one or more electricmotors, internal combustion engines, and external combustion engines.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered limiting of its scope, the invention will be describedand explained with additional specificity and detail through use of theaccompanying drawings, in which:

FIG. 1 is an illustration depicting one scenario for use of anautonomous control system 150, according to some example embodiments.

FIG. 2 is an illustration depicting another scenario according to oneexample embodiment.

FIG. 3 is an illustration depicting one example scenario for use of anautonomous control system 150, according to one example embodiment.

FIG. 4 is an illustration depicting a vehicle's rear wheel and axleassembly according to one example embodiment.

FIG. 5 is a schematic block diagram illustrating one embodiment of anautonomous control system 150 according to one example embodiment.

FIG. 6 is a schematic block diagram illustrating another embodiment ofan autonomous control system 150 according to an example embodiment.

FIG. 7 is a flow diagram illustrating a certain example embodiment.

FIG. 8 is a flow diagram illustrating another example embodiment.

FIG. 9 is a flow diagram illustrating one example embodiment of anothermethod.

FIG. 10 is a flow diagram illustrating one example embodiment of amethod for generating calibration polynomials that determine totalweight, according to one example embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

The description that follows includes systems, methods, techniques,instruction sequences, and computing machine program products thatembody illustrative embodiments of the disclosure. In the followingdescription, for the purposes of explanation, numerous specific detailsare set forth in order to provide an understanding of variousembodiments of the inventive subject matter. It will be evident,however, to those skilled in the art, that embodiments of the inventivesubject matter may be practiced without these specific details. Ingeneral, well-known instruction instances, protocols, structures, andtechniques are not necessarily shown in detail.

In various embodiments, a system as described herein determines a weightbeing hauled by a vehicle based many data points that include a measuredlongitudinal acceleration and a drive force, wherein the drive force isdetermined according to a calibrated polynomial for a current velocityof the vehicle.

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment. Thus, appearances of the phrases“in one embodiment,” “in an embodiment,” and similar language throughoutthis specification may, but do not necessarily, all refer to the sameembodiment, but mean “one or more but not all embodiments” unlessexpressly specified otherwise. The terms “including,” “comprising,”“having,” and variations thereof mean “including but not limited to”unless expressly specified otherwise. An enumerated listing of itemsdoes not imply that any or all of the items are mutually exclusiveand/or mutually inclusive, unless expressly specified otherwise. Theterms “a,” “an,” and “the” also refer to “one or more” unless expresslyspecified otherwise.

Furthermore, the described features, advantages, and characteristics ofthe embodiments may be combined in any suitable manner. One skilled inthe relevant art will recognize that the embodiments may be practicedwithout one or more of the specific features or advantages of aparticular embodiment. In other instances, additional features andadvantages may be recognized in certain embodiments that may not bepresent in all embodiments.

These features and advantages of the embodiments will become more fullyapparent from the following description and appended claims, or may belearned by the practice of embodiments as set forth hereinafter. As willbe appreciated by one skilled in the art, aspects of the presentinvention may be embodied as a system, method, and/or computer programproduct. Accordingly, aspects of the present invention may take the formof an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module,” or “system.”Furthermore, aspects of the present invention may take the form of acomputer program product embodied in one or more computer readablemedium(s) having program code embodied thereon.

Many of the functional units described in this specification have beenlabeled as modules, in order to more particularly emphasize theirimplementation independence.

For example, a module may be implemented as a hardware circuitcomprising custom VLSI circuits or gate arrays, off-the-shelfsemiconductors such as logic chips, transistors, or other discretecomponents. A module may also be implemented in programmable hardwaredevices such as field programmable gate arrays, programmable arraylogic, programmable logic devices or the like.

Modules may also be implemented in software for execution by varioustypes of processors. An identified module of program code may, forinstance, comprise one or more physical or logical blocks of computerinstructions which may, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of program code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.Where a module or portions of a module are implemented in software, theprogram code may be stored and/or propagated on in one or more computerreadable medium(s).

The computer readable medium may be a tangible computer readable storagemedium storing the program code. The computer readable storage mediummay be, for example, but not limited to, an electronic, magnetic,optical, electromagnetic, infrared, holographic, micromechanical, orsemiconductor system, apparatus, or device, or any suitable combinationof the foregoing.

More specific examples of the computer readable storage medium mayinclude but are not limited to a portable computer diskette, a harddisk, a random access memory (RAM), a read-only memory (ROM), anerasable programmable read-only memory (EPROM or Flash memory), aportable compact disc read-only memory (CD-ROM), a digital versatiledisc (DVD), an optical storage device, a magnetic storage device, aholographic storage medium, a micromechanical storage device, or anysuitable combination of the foregoing. In the context of this document,a computer readable storage medium may be any tangible medium that cancontain, and/or store program code for use by and/or in connection withan instruction execution system, apparatus, or device. Computer readablestorage medium excludes computer readable signal medium and signals perse.

The computer readable medium may also be a computer readable signalmedium. A computer readable signal medium may include a propagated datasignal with program code embodied therein, for example, in baseband oras part of a carrier wave. Such a propagated signal may take any of avariety of forms, including, but not limited to, electrical,electro-magnetic, magnetic, optical, or any suitable combinationthereof. A computer readable signal medium may be any computer readablemedium that is not a computer readable storage medium and that cancommunicate, propagate, or transport program code for use by or inconnection with an instruction execution system, apparatus, or device.Program code embodied on a computer readable signal medium may betransmitted using any appropriate medium, including but not limited towire-line, optical fiber, Radio Frequency (RF), or the like, or anysuitable combination of the foregoing.

In one embodiment, the computer readable medium may comprise acombination of one or more computer readable storage mediums and one ormore computer readable signal mediums. For example, program code may beboth propagated as an electro-magnetic signal through a fiber opticcable for execution by a processor and stored on RAM storage device forexecution by the processor.

Program code for carrying out operations for aspects of the presentinvention may be written in any combination of one or more programminglanguages, including an object oriented programming language such asJava, Smalltalk, C++, PHP or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages. The program code may execute entirely on theuser's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

The computer program product may be shared, simultaneously servingmultiple customers in a flexible, automated fashion. The computerprogram product may be standardized, requiring little customization andscalable, providing capacity on demand in a pay-as-you-go model. Thecomputer program product may be stored on a shared file systemaccessible from one or more servers.

The computer program product may be integrated into a client, server andnetwork environment by providing for the computer program product tocoexist with applications, operating systems and network operatingsystems software and then installing the computer program product on theclients and servers in the environment where the computer programproduct will function.

In one embodiment software is identified on the clients and serversincluding the network operating system where the computer programproduct will be deployed that are required by the computer programproduct or that work in conjunction with the computer program product.This includes the network operating system that is software thatenhances a basic operating system by adding networking features.

Furthermore, the described features, structures, or characteristics ofthe embodiments may be combined in any suitable manner. In the followingdescription, numerous specific details are provided, such as examples ofprogramming, software modules, user selections, network transactions,database queries, database structures, hardware modules, hardwarecircuits, hardware chips, etc., to provide a thorough understanding ofembodiments. One skilled in the relevant art will recognize, however,that embodiments may be practiced without one or more of the specificdetails, or with other methods, components, materials, and so forth. Inother instances, well-known structures, materials, or operations are notshown or described in detail to avoid obscuring aspects of anembodiment.

Aspects of the embodiments are described below with reference toschematic flowchart diagrams and/or schematic block diagrams of methods,apparatuses, systems, and computer program products according toembodiments of the invention. It will be understood that each block ofthe schematic flowchart diagrams and/or schematic block diagrams, andcombinations of blocks in the schematic flowchart diagrams and/orschematic block diagrams, can be implemented by program code. Theprogram code may be provided to a processor of a general purposecomputer, special purpose computer, sequencer, or other programmabledata processing apparatus to produce a machine, such that theinstructions, which execute via the processor of the computer or otherprogrammable data processing apparatus, create means for implementingthe functions/acts specified in the schematic flowchart diagrams and/orschematic block diagrams block or blocks.

The program code may also be stored in a computer readable medium thatcan direct a computer, other programmable data processing apparatus, orother devices to function in a particular manner, such that theinstructions stored in the computer readable medium produce an articleof manufacture including instructions which implement the function/actspecified in the schematic flowchart diagrams and/or schematic blockdiagrams block or blocks.

The program code may also be loaded onto a computer, other programmabledata processing apparatus, or other devices to cause a series ofoperational steps to be performed on the computer, other programmableapparatus or other devices to produce a computer implemented processsuch that the program code which executed on the computer or otherprogrammable apparatus provide processes for implementing thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The schematic flowchart diagrams and/or schematic block diagrams in theFigures illustrate the architecture, functionality, and operation ofpossible implementations of apparatuses, systems, methods and computerprogram products according to various embodiments of the presentinvention. In this regard, each block in the schematic flowchartdiagrams and/or schematic block diagrams may represent a module,segment, or portion of code, which comprises one or more executableinstructions of the program code for implementing the specified logicalfunction(s).

It should also be noted that, in some alternative implementations, thefunctions noted in the block may occur out of the order noted in theFigures. For example, two blocks shown in succession may, in fact, beexecuted substantially concurrently, or the blocks may sometimes beexecuted in the reverse order, depending upon the functionalityinvolved. Other steps and methods may be conceived that are equivalentin function, logic, or effect to one or more blocks, or portionsthereof, of the illustrated Figures. Although various arrow types andline types may be employed in the flowchart and/or block diagrams, theyare understood not to limit the scope of the corresponding embodiments.Indeed, some arrows or other connectors may be used to indicate only thelogical flow of the depicted embodiment. For instance, an arrow mayindicate a waiting or monitoring period of unspecified duration betweenenumerated steps of the depicted embodiment. It will also be noted thateach block of the block diagrams and/or flowchart diagrams, andcombinations of blocks in the block diagrams and/or flowchart diagrams,can be implemented by special purpose hardware-based systems thatperform the specified functions or acts, or combinations of specialpurpose hardware and program code.

FIG. 1 is an illustration depicting one scenario for use of anautonomous control system 150, according to some example embodiments. Inone embodiment, the autonomous control system determines vehicleperformance conditions that increase accuracy of total weightdetermination as described herein. Certain performance parametersinclude, but are not limited to, lateral acceleration, engine speed,longitudinal acceleration, transmission gear selection, application ofbrakes, operation of energy recovery systems, operation of special orunique operation modes, or other, or the like.

As will be further described herein, determination of lateralacceleration using the Earth as a point of reference allows such anautonomous control system 150 to account for the force of gravity invarious drive force calculations. Accordingly, the autonomous controlsystem 150 performs accurately in a wide variety of slopes and varyingterrain.

In order to accurately determine the system weight, the pitch of thevehicle must be determined. Vehicle pitch is monitored when the vehiclecomes to a stop. This pitch is then compared to the pitch when thevehicle starts accelerating forward. The difference of these two pitches(pitch at rest vs. pitch upon forward motion) due to a load in the bedof the vehicle, must be corrected to adjust the accelerometers for thisbias.

When the vehicle is turning, the data must be filtered out. Turn eventsare sensed through the lateral accelerometers. However, many roads havea crown, so the vehicle may actually be travelling in a straight line.In this case, the lateral accelerometer will show a value, filtering outwhat should be good data. Roll compensation solves this problem. Thelateral accelerometer is zeroed out right before the vehicle takes off,and filters only for changes to that accelerometer. A steering wheelsensor or gyro may also sense turning events.

The accelerometers determine their orientation in a vehicle a fewseconds after the diagnostic connector is plugged in. Many users mayhave modified the suspension of their vehicle so that the pitch is nolonger the same as at the factory. By re-orienting during install, acustom accelerometer setting for each vehicle is established,determining longitudinal, lateral and vertical axes no matter what theorientation of the vehicle.

Reset logic provides for all settings to be reset to zero and the systemto be restarted upon the occurrence of any one or more of the following:complete system reset upon vehicle engine being turned off; completesystem reset upon vehicle pitch and shaking detection indicating loadshift; and complete system reset upon vehicle travelling in reversedirection.

Since a vehicle may have been modified after the factory, axle and tiresize detection is also calculated in one embodiment of the invention.Axle ratio and tire size detection is determined when the vehicle istravelling at a speed of between 60 mph to 80 mph, and O_(g−)(−0.2 g),Engine RPM/vehicle speed is recorded. This ratio enables the algorithmto learn the vehicle's axle ratio and tire size. Once recorded, it isused to correct the mass calculated from the algorithm.

After determining that the vehicle is operating within certainperformance thresholds, the autonomous control system 150 storesperformance data pairs including, longitudinal acceleration and a driveforce. As will be further described herein, the drive force may bedetermined based on calibration polynomials generated by the autonomouscontrol system 150.

The autonomous control system 150 then determines the slope of a linethat approximates the data pairs wherein the slope of the line indicatesa total weight. The autonomous control system 150 then subtracts a knownweight of the vehicle to determine the total weight of the vehicle. Ofcourse, one skilled in the art may recognize other ways to determine theslope of a line that approximates a set of data points and thisdisclosure is meant to include all such ways. Accordingly, theautonomous control system 150 determines a total vehicle weight based,at least in part, on learned drive force behavior of the vehicle andcurrent drive force compared with longitudinal acceleration.

The autonomous control system 150 may then display the determined totalweight to a driver of the vehicle. This allows the driver to adjustoperation of the vehicle based on knowledge of the total weight. Forexample, in response to total weight that is 90% of the vehicle's haulcapacity, the user may understand to apply braking earlier or moreaggressively. In another example, the user may drive more slowly, oradjust other operation of the vehicle in order to maintain safeoperating conditions.

In another embodiment, the autonomous control system 150 activelyadjusts operation of the vehicle without user intervention. For example,the autonomous control system 150 may, in response to total weightexceeding a threshold value, increase the brake gain signal to a brakecontroller. In another embodiment the autonomous control system 150 mayadjust the acceleration and in another embodiment the steering of thevehicle.

Therefore, the operation of the vehicle, from the user's frame ofreference may not be significantly different than operation of thevehicle while hauling significant weight. Furthermore, as will bedescribed, the autonomous control system 150 adjusts systems thatcontrol operation of the vehicle based on the determined total weight.Thus various systems that control operation of the vehicle may beconfigured to perform with consideration of the actual total weight.

A vehicle hauling a weight as described herein may include a vehiclecarrying or towing another weight. In one example, a vehicle hauling aload may include a truck towing one or more trailers. In anotherexample, a vehicle hauling a load may include a truck carrying goods orother items in a bed of the truck. In another example, a vehicle haulinga load may include an automobile with significant weight beyondpassengers where the weight may alter the performance characteristics ofthe vehicle. Of course, one skilled in the art may appreciate a widevariety of other vehicles carrying or towing trailers, goods, items,other vehicles, recreational vehicles, motorcycles, all-terrainvehicles, cargo, other items, or the like.

In one embodiment, determining a weight of goods or items being carriedor hauled helps ensure that the vehicle operates within one or moresafety parameters. In one example, the autonomous control system 150determines if the weight being hauled exceeds a safety threshold. In oneexample, a manufacturer for the vehicle may have specified a maximum towcapacity.

In another embodiment, the autonomous control system 150 communicatesvehicle control and performance data to the user or driver via a display104 and on the sound system 106 via display 108. This data may also becommunicated via sound system 106 in the form of programmable alertsounds and verbal messages. The autonomous control system 150 mayfurther allow user input in the form of voice commands to allowmodifications to the programming and communication to other vehicleswith a similar autonomous control system 150.

As indicated in FIG. 1, the autonomous control system 150 may beimplemented as a physical hardware module that plugs into a diagnosticport for the vehicle. Thus the autonomous control system 150communicates with a computer for the vehicle to determine variousvehicle performance properties, such as, but not limited to, enginespeed, throttle position, a transmission gear selection, special and/orunique operating modes, or the like, as described herein. In certainembodiments, the autonomous control system 150 may be purchased by auser and installed in any vehicle with a capable communication port.Thus, the autonomous control system 150 may be installed in a vehicleafter purchase of the vehicle and does not need to be installed by amanufacturer of the vehicle.

In another embodiment, the autonomous control system 150 may transmitthe determined total weight to a display 104. Information regarding theperformance, operation and response of the vehicle via an OEMimplementation, or on the digital readout display 108 of the vehicle'scar sound system 106. A driver of the vehicle may view the display andoperate the vehicle according to the displayed information, or performother appropriate actions having knowledge of the performance andresponse of the vehicle. In other example embodiments, the display 104is configured to display messages, alerts, adjustments, warnings, orother indications to a user.

FIG. 2 is an illustration depicting one example scenario for use of anautonomous control system 150, according to one example embodiment. Inthis example embodiment, the vehicle is a truck 202, and the weightbeing hauled is a trailer 206.

The amount of weight included in the trailer 206 may vary widely basedon an amount of equipment being stored in the trailer 206. Therefore, adriver of the vehicle may or may not realize the haul weight of thetrailer 206. This presents a danger to the driver of the vehicle.Therefore, the autonomous control system 150, according to oneembodiment, assists a user to safely operate a vehicle that is hauling aweight. The autonomous control system 150, according to anotherembodiment, sends commands to the controller which safely operates avehicle that is hauling a weight by adjusting the steering, accelerationand the braking of the vehicle.

In this example embodiment, the autonomous control system 150communicates with the vehicle control system via a wireless connection208. In certain embodiments, the wireless connection 208 communicatesinformation to other vehicles with similar autonomous control systems,roadway control systems, master stations and all other applicablemonitoring and control systems associated with the vehicles on the roadand near the roadway. In one example, the autonomous control system 150may be communicating using Bluetooth™, near field communications (NFC),WIFI, low bandwidth, high bandwidth, mesh networks such as ZigBee, viacell phone radio systems, satellite radio systems, or any other wirelesscommunication protocol as one skilled in the art may appreciate. Inanother embodiment, the autonomous control system 150 calculates thetotal vehicle weight including all haul weights comprising weight 204 inthe bed of the truck, weights inside the vehicle, the weight of thingsbeing towed, the weight of trailer 206, and all weight being hauled bythe vehicle.

FIG. 3 is an illustration depicting an example embodiment of a truck 202equipped with an autonomous control system 150 following a car 302 whichis also equipped with a similar autonomous control system 150 on aroadway 320. The two vehicles communicate via signal 310 from the truckand 312 from the car. Information regarding the car performance isreceived by the autonomous control system 150 of truck 202. Thisinformation includes not only the weight of the car 302, but also howthe weight of the car 302 influences the car's behavior on the roadway320. As the car 302 passes over a slick section 325 on the roadway, theautonomous control system 150 of the car adjusts the acceleration,braking and steering as it passes over the slick section 325 in order toprevent sliding off the road. This information which comprises theweight of car 302, it's response based on road conditions comprisingfeedback response data when tires are contacting slick section 325, theactions carried out by the control system in response to the slippage ofthe tires when accelerating or decelerating, along with data regardingbehavior of the vehicle and response to the adjustments after bringingthe car 302 back into safe control. By relaying this data in real timeto the truck 202, the autonomous control system 150 of the truck 202 mayinterpret and scale the data to apply the response data of the car 302in a way that informs the control system to prepare for the aberrantroad conditions prior to arriving at the slick section 325 or otheraberrant road conditions in a way that is specific to the truck 202.Since the truck 202 has a different mass than the car 302, the controlsystem modifies the calculations based on the weight and response dataof the car 302, scaling as required to meet the specific requirementsfor the control of the truck 202.

FIG. 4 is an illustration depicting another example according to oneexample embodiment. A vehicle's rear wheel and transaxle assembly 400 isshown. The factory preset axle ratio 454 in the transaxle 452 may havebeen altered after the factory. Similarly, the tire size 456 may havealso been changed. Axle ratio 454 and tire size 456 detection isdetermined when the vehicle is travelling at a speed of between 60 mphto 80 mph, and Og−(−0.2 g), Engine RPM/vehicle speed is recorded. Thisratio enables the algorithm to learn the vehicle's axle ratio and tiresize. Once recorded, it is used to correct the mass calculated from thealgorithm.

FIG. 5 is a schematic block diagram illustrating one embodiment of anautonomous control system 150, according to one example embodiment. Inthis example embodiment, the autonomous control system 150 includesprocessors 102, memory 104, a drive force module 106, a vehicle pitchand roll module 108, one or more accelerometers 210, a performancemodule 240, an interface module 220, a data module 250, a weight module230, an operation module 260, and an output module 280 and a controlmodule 290.

Processors 102 include any and/or all processors capable of executingexecutable code as described herein. The memory 104 includes the variouscomputer-readable storage mediums described herein. According to oneexample embodiment, the memory 104 stores executable code for causingthe processor 102 to perform various functions and/or methods asdescribed herein regarding the modules (e.g. the performance module 240,the interface module 220, the data module 250, the weight module 230,the brake gain module 260, brake signal module 280 and brake controlmodule 290).

In one example embodiment, the one or more accelerometers 210 includes atriaxial accelerometer. As described herein, and as one skilled in theart may appreciate, the triaxial accelerometer senses acceleration, at asingle-point, in three planes. Each of the three planes may beperpendicular to another of the three planes. According to a Cartesiancoordinate system, the three planes are represented by X, Y, and Zplanes as one skilled in the art may appreciate. In one embodiment, thetriaxial accelerometer measures acceleration and transmits theacceleration in any and/or all of the planes to the interface module220. The triaxial accelerometer also includes the force of gravity inthe acceleration values.

In another embodiment, the accelerometers 210 include three distinctaccelerometers configured to sense acceleration along different axis. Ofcourse, one skilled in the art may recognize other ways to detectacceleration in three different planes and this disclosure is meant toinclude all such ways. Furthermore, the triaxial accelerometer may notbe limited regarding frequency range, amplitude range, resonance,sensitivity, temperature range, shock range, or the like as one skilledin the art may appreciate.

The accelerometer(s) 210 therefore, determine an acceleration of theautonomous control system 150 including the force of gravity. Therefore,based on measurements by the accelerometer(s) 210, the autonomouscontrol system 150 also determines an orientation of the autonomouscontrol system 150. Accordingly, the autonomous control system 150 maydetermine whether the vehicle is traveling up a hill, down a hill, or isdriving along an incline.

In one embodiment, the interface module 220 is configured to retrieveone or more values. In one example, the interface module 220 receives aninitial weight for a vehicle not including any hauled weight from a userinterface. For example, the interface module 220 receives a manufacturervalue for the vehicle weight from a user, manufacturer, or 3rd partysource of the vehicle.

In another example embodiment, the interface module 220 retrieves one ormore values via a communication port for the vehicle. For example, theinterface module 220 may communicate with a computer for the vehicle viaan On-Board-Diagnostics (OBD) interface, and ODB-II interface, or other,or the like. In another embodiment, the interface module 220 may receivevehicle velocity, engine speed, or other vehicle performance parameters,or the like via the diagnostic port.

In one example embodiment, the autonomous control system 150 requestsvehicle velocity and engine RPM's from a vehicles computing device todetermine calibration polynomials and subsequently determine totalweight. Accordingly, the interface module 220 does not need othervariables from a computing device for the vehicle. [0070] In oneembodiment, the interface module 220 retrieves one or more accelerationvalues from one or more accelerometers 210. The interface module 220 maydifferentiate between lateral acceleration, longitudinal acceleration,and vertical acceleration based, at least in part on measurements fromthe accelerometers 210. Therefore, in certain embodiments, the interfacemodule 220 may determine longitudinal acceleration using one or moreaccelerometers.

In another embodiment, the interface module 220 determines engine speedby alternator noise on a power line of the vehicle. In one embodiment,the interface module 220 determines vehicle velocity and/or accelerationfrom a GPS device, or other location device as one skilled in the artmay appreciate. In one embodiment, the interface module 220 includes anorientation sensor. For example, the interface module 220 may senseorientation in order to determine acceleration values, such as, but notlimited to, lateral acceleration, longitudinal acceleration, or thelike. Therefore, in certain embodiments, the interface module 220 maydetermine acceleration values regardless of an orientation of theautonomous control system 150.

In another embodiment, the interface module 220 includes one or morebuttons to receive commands from a user. For example, the interfacemodule 220 may include a button for a user to press that may indicate acalibration procedure is to be initiated. In response to the interfacemodule 220 detecting a press of the button, the data module 250initiates a calibration procedure as will be further described.

In certain embodiments, the performance module 240 determines whether avehicles performance falls within a set of threshold ranges. In someexamples, the autonomous control system 150 determines whether lateralacceleration, engine speed, longitudinal acceleration, transmissiongears, and other performance parameters are within respective thresholdranges.

In certain embodiments, the drive force module 106 determines the totalof all drive forces including electric motors, internal combustionengines and all other devices providing positive force to move thevehicle in the desired direction, typically forward motion. In otherembodiments, the drive force module includes all positive and negativedrive forces including brakes or other devices that inhibit the positiveforce which normally moves the vehicle in the desired direction.

In other embodiments, the vehicle pitch and roll module 108 determinesthe pitch and roll of the vehicle based on accelerometer data along withdata provided by the on-board computer and on board processors. Inanother embodiment, pitch and roll data comes from wireless dataprovided from accelerometers in personal electronic devices.

For example, the performance module 240 determines whether lateralacceleration falls between −0.05 standard gravity units and +0.05standard gravity units. In response to the lateral acceleration beingwithin the threshold range, the data module 250 records one or more datapairs including drive force and longitudinal acceleration.

In another example, performance module 240 determines whether enginespeed for the vehicle is within a threshold range. For example, acombustion engine operates more or less efficiently at different enginespeeds, therefore, the autonomous control system 150 may determine aweight being hauled by the vehicle in response to the combustion engineoperating within a threshold range of revolutions per minute (RPM's).For example, the performance module 240 determines that in response tothe engine operating at between 900 RPM's and 3000 RPM's, the datamodule 250 may collect one or more data points.

In another example, the performance module 240 determines whether anengaged drivetrain gear differs from a drivetrain gear engaged while thecalibration module generated one or more calibration polynomials asdescribed herein.

In another example, exterior forces that effect performance of a vehicleare less at lower velocities. Examples includes, air resistance, oilresistance, wheel bearing resistance, internal drag forces, such as, butnot limited to, friction, wear, powertrain friction or drag. These otherforces may or may not act along the longitudinal axis of the vehicle.Therefore, in order to increase accuracy of weight determinations, theperformance module 240 may also wait for the vehicle's velocity to bewithin a threshold range before the data module 250 records one or moredata pairs. In one example, the performance module 240 determineswhether the vehicle is moving between 2 and 20 kilometers per hour(KPH).

In another example, a vehicle that is accelerating is not typicallyapplying brakes or other forces, therefore, performance module 240 mayalso ensure that the vehicle is accelerating before the data module 250stores data pairs. In one example, the performance module 240 determinesthat a longitudinal acceleration for the vehicle is between 0.05standard gravity units and 1 standard gravity units. In response, thedata module 250 stores one or more data pairs as described herein.

In another example embodiment, the performance module 240 determineswhether the vehicle's engine is operating in any special or uniquemodes. For example, in response to determining that the vehicle's engineis operating in a decreased capacity (e.g. a fuel efficiency mode), thedata module 250 may not store data pairs. Special or unique modesincludes, but is not limited to, use of hybrid systems, electric driveassistance, power recovery modes, fuel efficiency modes, partial engineusage, or other non-conventional or reduced power engine operationmodes.

In one example embodiment, in response to the performance module 240determining that one or more vehicle performance parameters are withinrespective threshold ranges, the data module 250 stores data pairsrepresenting a current operating state for the vehicle. The data pairsinclude drive force and longitudinal acceleration. [0080] In anotherembodiment, the interface module 220 may divide the acceleration intomultiple components (e.g. 3 components). For example, the performancemodule 240 may determine that a portion of the acceleration may belateral acceleration, a portion for longitudinal acceleration andanother portion for vertical acceleration. Lateral acceleration may beassociated with a change in lateral movement not associated with forcefrom the engine. Therefore, in certain embodiments, the performancemodule 240 may determine a portion of the total acceleration associatedwith applied engine force (longitudinal acceleration). This longitudinalacceleration may include acceleration along or parallel with the axisvehicle movement. Lateral acceleration may be perpendicular to thelongitudinal axis of the vehicle.

The data module 250 stores data pairs representing the currentperformance of the vehicle. The data pairs include a drive force and alongitudinal acceleration. In one embodiment, the data module 250 maygeneralize drive forces (F_(Drive)) by generally combining drag forces(F_(Drag)) and acceleration (F_(Accel)) forces using the followingequation (Equation 1):

F _(Drive) =F _(Drag) +F _(Accel)

In another embodiment, a vehicle may include a transmission with atorque converter. A torque converter, in certain embodiments, maydecouple the transmission and the engine of the vehicle. This may allowthe vehicle to stop moving although the engine for the vehicle maycontinue operating. A torque converter may also include an impeller(i.e. a pump) that may be attached to the engine, and a turbine that maybe attached to a transmission for the vehicle. In one example, hydraulicfluid may be pumped from the impeller to the turbine. The increasedhydraulic pressure from the impeller may cause the turbine to spin at asimilar speed which may increase torque transmitted to the transmission.

Therefore, where engine speed is represented as S_(E), and Vehiclevelocity is represented as S_(V), turbine torque (T_(T)) may berepresented as a function of engine speed and vehicle velocity asfollows (Equation 2):

T _(T) =f(S _(E) , S _(V))

In one embodiment, a transmission ratio may directly relate turbinetorque to drive force. Furthermore, turbine torque may be represented bya function of engine speed and vehicle velocity. For example (Equation3):

F _(Drive) =f(T _(T))

Combining equations 2 and 3 allows drive force to be represented as afunction of engine speed and vehicle velocity (Equation 4):

F _(Drive) =f(S _(E) , S _(V))

Solving equation 1 for the force of acceleration results in (Equation5):

F _(Accel) =F _(Drive) −F _(Drag)

Drag force(F_(Drag)) may be influenced by many factors. Any of theseDrag force (F_(Drag)) factors may vary with speed. In one example, airresistance may increase with vehicle velocity. In another example,internal friction may increase as components spin faster. Therefore,drag force may be written as a function of vehicle velocity resulting in(Equation 6):

F _(Drag) =f(S _(V))

In other embodiments, drive force may also be depicted as a function ofengine speed and vehicle velocity. Therefore (Equation 7):

F _(Drive) −F _(Drag) =f(S _(E) , S _(V))

Further noting that a force of acceleration is the mass (m) (e.g.,weight) being accelerated multiplied by the acceleration (a) results in(Equation 8):

F _(Accel) =m·a

In one embodiment, longitudinal acceleration may be depicted as a_(lon)the force of acceleration may be calculated as follows (Equation 11):

F _(Accel) =C ₂ ·a _(lon) +C ₁

The calibration module 270 may perform regression analysis on theresulting data pairs and the haul weight may be C₂ minus the calibrationweight (the weight of the vehicle performing the hauling). In responseto the data module 250 storing 50 or more data pairs, and the regressionerror falling below 0.05, the output module 280 may display the haulweight. In one specific example, the calibration module 270 usesrecursive least squares as one skilled in the art may appreciate. Inother examples, the calibration module 270 generates a cubic or 4thorder polynomial.

In order to initiate the regression analysis, the y intercept of theforce vs. acceleration curve is set to zero. This allows for a readingto be taken with just one set of data points, even if they are clusteredtogether.

In one embodiment, the weight may be determined using the followingequation where n=the number of data pairs of drive force andlongitudinal acceleration (equation 12):

$C_{2} = \frac{{n \cdot {\sum^{n}\left( {a_{lon} \cdot F_{Drive}} \right)}} - {\sum^{n}{\left( F_{Drive} \right) \cdot {\sum^{n}\left( a_{lon} \right)}}}}{{n \cdot {\sum^{n}\left( a_{lon}^{2} \right)}} - {\sum^{n}\left( a_{lon} \right)^{2}}}$

In one example embodiment, the weight module 230 is configured todetermine the weight being hauled by the vehicle by determining a slopeof a line that approximates the set of data pairs acquired by the datamodule 250. The weight module 230 may determine a line that approximatesthe data pairs in any way as one skilled in the art may appreciate. Inone example, the weight module 230 applies a linear regressionalgorithm, or other, or the like. In another example embodiment, theweight module 230 applies the linear regression algorithm until theerror falls below 0.05.

The weight module 230 then determines the slope of the line resultingfrom the linear regression algorithm. In this example embodiment, theslope of the line represents the total weight (including the weight ofthe vehicle and the weight being hauled by the vehicle). Therefore, theweight module 230 also determines the amount of weight being hauled bythe vehicle by subtracting the known weight of the vehicle from thetotal weight.

In one embodiment, the operation module 260 alters vehicle operationbased on the determined vehicle haul weight. In one example, theoperation module 260 increases a gain for a braking system in responseto determining that a determined haul weight falls within a range ofthreshold values. In one example, where the haul weight exceeds 90% ofthe maximum haul weight for the vehicle, the operation module 260increases brake gain signal to a maximum value. The output module 280transmits the modified brake gain signal to the control module 290. Thecontrol module 290 causes the braking system to deliver the force scaledaccording to the gain signal to the trailer brakes. In another example,modifying a gain for a braking system of the vehicle may accommodateincreased haul weight for an automated collision detection system.Therefore, in response to an anticipated collision, the collisiondetection system may increase braking automatically based on the vehiclehaul weight.

The autonomous control system comprises the invented logic integratedwithin. An integrated autonomous control system is similar to theaftermarket version, but would be integrated into the vehicle, sharingsome sensor inputs (such as accelerometer) with other vehicle systems.

FIG. 6 is a schematic block diagram illustrating another embodiment ofan autonomous control system 150, according to one example embodiment.In this example, the autonomous control system 150 includes processors102, memory 104, a drive force module 106, a vehicle pitch and rollmodule 108, one or more accelerometer(s) 210, the performance module240, the interface module 220, the data module 250, the weight module230, the operation module 260, a calibration module 270, and an outputmodule 280. The processor 102, the memory 104, the accelerometer(s) 210,the performance module 240, the interface module 220, the data module250, the weight module 230, the operation module 260, a calibrationmodule 270, and an output module 280 may or may not be substantiallysimilar to modules depicted in FIG. 5. Communication module 295 receivesand transmits information regarding the weight of the vehicle and howthat weight influences or changes the response and performance of thevehicle to other vehicles on the road with similar autonomous controlsystems. This communication preferably is accomplished via knownwireless methods. In addition to sending and receiving information anddata from other vehicles equipped with similar autonomous controlsystems, the communication module also communicates with other roadwaycontrol systems for the monitoring and control of autonomous vehicles.Data regarding road conditions, the behavior of vehicles on the roadwayand how this behavior changes in real time (for example—tires slippingon ice or other slick material on the roadway) is communicated. Thisdata potentially changes over time, so must be continuously communicatedwhen certain conditions exist. These conditions can be pre-set in thelogic of the control system, programmed by the user, and be determinedfrom sensors on the vehicles with autonomous control systems and roadwaysensors. One example of the rate of slippage on ice changing is when thevehicle is a truck hauling a trailer and the trailer becomes separatedfrom the truck. The new weight of the truck is much lighter, so the rateof slippage would be less with the lower mass. This resolution of datais important to communicate to the other vehicles and roadway controlsystems. The communication module 295 sends and receives data to allother control systems associated with the monitoring and control ofvehicles on and off the road.

In one embodiment, the autonomous control system 150 includes an outputmodule 280 that is configured to transmit the determined total weight toa remote system for display.

In certain embodiments, the drive force module 106 determines the totalof all drive forces including electric motors, internal combustionengines and all other devices providing positive force to move thevehicle in the desired direction, typically forward motion. In otherembodiments, the drive force module includes all positive and negativedrive forces including brakes or other devices that inhibit the positiveforce which normally moves the vehicle in the desired direction.

In other embodiments, the vehicle pitch and roll module 108 determinesthe pitch and roll of the vehicle based on accelerometer data along withdata provided by the on-board computer and on board processors. Inanother embodiment, pitch and roll data comes from wireless dataprovided from accelerometers in personal electronic devices.

In one embodiment, the output module 280 outputs one or more values fordisplay to a user or driver of the vehicle. Informing a driver of avehicle that is hauling a load may increase the user's ability tocorrectly estimate the performance capabilities of the vehicle.Accordingly, a user may be better informed and more appropriately reactto real driving scenarios.

In another embodiment, the output module 280 may notify a user or driverof the vehicle in response to determining that the vehicle weight(including any load) exceeds a recommended maximum load weight. In oneexample, the output module 280 may transmit the determined load weightto a remote display via a wired or a wireless connection. For example,the output module 280 may transmit a value representing the load weightvia low energy Bluetooth, or other transmission medium as one skilled inthe art may appreciate.

In one embodiment, the output module 280 periodically updates adisplayed load weight. For example, the output module 280 updates theload weight every 10 seconds, in response to a new weight beingdetermined, or other interval.

In another example embodiment, the calibration module 270 generates asecond order polynomial that approximates a calibration drive force andengine speed curve for each velocity of the vehicle. The data module 250may use these polynomials to determine drive force as will be furtherdescribed. The calibration module 270 may perform quadratic regressionanalysis on data pairs that include calibration drive force and enginespeed.

As previously described, the performance module 240 determines whethervehicle performance parameters fall within respective threshold ranges.Therefore, the calibration module 270 may generate the polynomials insimilar conditions as the weight module 230 determines a weight beinghauled by the vehicle. In one specific example, the calibration module270 delays generating the polynomials in response to the vehicletraveling up a hill, down a hill, or is at another incline.

In one embodiment, the interface module 220 receives the known weight ofthe vehicle and the force of acceleration may be measured by the one ormore accelerometer(s) 210. The drive force minus the drag force may besolved as a function of engine speed and vehicle velocity. In otherembodiments, this calibration method may not require the drag force tobe estimated or learned.

In certain embodiments, the data module 250 stores data pairs thatincludes engine speed and a calibration drive force. Plotting multipledata points may reveal a quadratic trend in the relationship betweenengine speed and the drive force. The weight module 230 may performregression analysis on the data points to determine coefficients of aquadratic polynomial that best fits the recorded data points. After theregression error decreases to an acceptable value, the weight module 230stores the coefficient values for the best fit polynomial. In oneexample, the weight module 230 stores the coefficient values after theregression error falls below 0.05. Of course, other values may be usedas one skilled in the art may appreciate.

Because the data pairs include motor speed and drive force, factorsdownstream of the motor are accounted for in the calibrationpolynomials. For example, because each velocity has a differentassociated polynomial, the polynomials for higher velocities naturallyinclude drag effects due to air resistance, internal friction, and allother forces that effect acceleration of the vehicle are accounted for.In one example, larger tires increase drag and the calibrationpolynomials inherently include the increased drag. In another example, amodified final drive ratio, an updated or repaired torque converter ortransmission, or other changes that affect an amount of drive forcerequired to accelerate the vehicle are all accounted for in thecalibration polynomials.

In another example embodiment, the calibration module 270 recalibrates(e.g. generates new polynomials, or updated polynomial coefficients) inresponse to any of these effects changing. For example, the calibrationmodule 270 may instruct the user to request a recalibration in responseto installing different sized tires on the vehicle. In other examples,the calibration module 270 instructs the user to request recalibrationin response to any of the following: vehicle body modifications (e.g. achange that affect wind resistance), changing an oil weight, changing afinal gear ratio, or other change that may affect an amount of driveforce needed to accelerate the vehicle.

In one embodiment, the weight module 230 estimates the weight of thevehicle (with trailer, cargo, goods, etc.) by calculating the force ofacceleration as a function of engine speed (S_(E)) as previouslydescribed. In one example, a quadratic equation may include a threecoefficient values, CO, C1, and C2. The quadratic equation may take theform (Equation 9):

C ₂ ·S _(E) ² +C ₁·(S _(E))+C ₀

Therefore (Equation 10):

F _(Accel)(C ₂ ·S _(E) ² +C ₁ ·S _(E) +C ₀)=m·a

In one embodiment, the calibration module 270 may determine weight ofthe vehicle including hauled goods by plotting the force of acceleration(F_(Accel)) versus actual acceleration (a). The plot may indicate alinear trend. The calibration module 270 may perform regression analysisto find a coefficient representing a difference between the force ofacceleration and weight multiplied by the acceleration plus thecoefficient.

In another embodiment, the weight module 230 estimates the weight of thevehicle using the coefficients (C2, C1, Co) used to calculate the forceof acceleration. In another embodiment, the weight module 230 may forgetcoefficient values, data points, or the like in response to beingpowered down. This may allow the calibration module 270 to determine newcoefficient values each time the vehicle is power cycled. In anotherembodiment, the calibration module 270 provides a button for a user. Inresponse to a user pressing the button, the calibration module 270 mayerase current coefficient values and may determine new coefficientvalues. Therefore, in certain embodiments, the calibration module 270determines new coefficient values each time a user changes a loadweight, or the like, for the vehicle.

In one example, the performance module 240 determines if vehiclevelocity falls between 2 and 20 miles per hour. In another example, theperformance module 240 determines if engine speed is above an idle speed(e.g. 900 RPM's). In another example, the performance module 240determines if a transmission for the vehicle is operating in a firstgear. For example, the performance module 240 determines if atransmission for the vehicle is operating in a first gear based on acomparison between engine speed and vehicle velocity. In anotherexample, the performance module 240 determines if the vehicle iscurrently experiencing low lateral acceleration as compared withlongitudinal acceleration. For example, if lateral acceleration is 10%or less of the longitudinal acceleration. In another example, thecalibration module 270 may determine if the vehicle pitch rate fallsbelow a threshold value, such as, but not limited to 5%. In anotherexample, the performance module 240 determines if an engine for thevehicle is currently operating within a temperature range. In a furtherembodiment, the performance module 240 determines if one or more of theforegoing conditions are met.

In response to determining if one or more inputs fall within thresholdvalues, the calibration module 270 may multiply the acceleration by theuser entered weight to calculate the drive force. The calibration module270 may store the drive force in tables by velocity. Because the datamodule 250 stores the drive force due to the weight and the measuredlongitudinal acceleration, the data pairs inherently include otherforces that affect the acceleration. Therefore, in one example, as windresistance increases at higher velocities, the association between driveforce and acceleration includes these forces without measuring the windresistance at the higher velocities. For example, because the increasedwind resistance ultimately affects the drive force I accelerationrelationship, the calibration module 270 accommodates these and evenother potentially unknown forces by separating the data pairs intoseparate table by velocity of the vehicle.

Furthermore, because the data pairs include drive force as determinedbased on the weight of the vehicle and measured acceleration, the driveforce is a calculated drive force instead of a measured one. Therefore,the relationship indicated in the data pairs recorded by the data module250 is based on drive force due to acceleration vs acceleration, whichof course, differs from measured drive force vs acceleration. As oneskilled in the art may appreciate, using a measured drive force in thisstage of the calculations would not effectively include other forcesthat affect the acceleration of the vehicle.

Also, the drive force (due to acceleration) provides increased accuracyby determining the drive force in a first selectable gear and doesrequire higher velocities to determine a weight being hauled by thevehicle.

The calibration module 270 may perform regression analysis on each tableof data for a given velocity of the vehicle. The error may also becalculated for each data set according to the regression analysis. Ifthe error does not fall below an error threshold value, the calibrationmodule 270 may perform further regression analysis. In one embodiment,if the error does not fall below the error threshold value after athreshold amount of time, the calibration module 270 may delete thecurrent coefficient values so that they are not used in weightestimation. If the error falls below the error threshold value, thecalibration module 270 may store the resulting polynomial coefficientsas previously described.

FIG. 7 is a flow diagram illustrating one example embodiment of a method700 for determining total weight, according to one example embodiment.Operations in the method 700 may be performed by the autonomous controlsystem 150, using modules described above with respect to FIGS. 5 and 6.As shown in FIG. 7, the method 700 includes operations 710, 720, 730,740, 750, and 760 and 770.

In one embodiment, the method 700 begins and at operation 710, theperformance module 240 determines that one or more vehicle performanceparameters fall within respective threshold ranges. The method 700continues at operation 720 and the data module 250 stores a plurality ofdata pairs. In another embodiment, the storing is in response to thevehicle parameters being within the respective threshold ranges. Inanother embodiment, each of the data pairs includes longitudinalacceleration and a drive force.

The method continues at operation 730 and the slope determination moduledetermines a slope of a line that linearly approximates the plurality ofdata pairs. In one embodiment, the slope of the line represents a totalweight that includes the weight of the vehicle and the weight beinghauled by the vehicle. The method 700 continues at operation 740 and theweight module determines the total weight of the vehicle including haulweight from the value representing the slope of the line in module 730.The method continues at operation 750 and the operation moduledetermines the response based on the weight of the vehicle. The responsedata is transmitted at operation 760 to other vehicles with similarautonomous control systems and other control systems as required. Thevehicle is controlled by the autonomous control system at operation 770.

FIG. 8 is a flow diagram illustrating another example embodiment of amethod for determining total weight, according to one exampleembodiment. Operations in the method 800 may be performed by theautonomous control system 150, using modules described above withrespect to FIGS. 5 and 6. As shown in FIG. 8, the method 800 includesoperations 810, 820, 830, 840, 850, 860, and 870.

The method 800 begins and at operation 810 the interface module 220retrieves one or more vehicle performance parameters as described inparagraph 72 through 79. In one example, the method 800 begins inresponse to an engine for the vehicle starting. The method 800 continuesat operation 820 and the performance module 240 determines whether thevehicle performance parameters are within respective threshold ranges.In response to one of the vehicle performance parameters not beingwithin a threshold range, the method 800 continues at operation 810.

In response to each of the vehicle performance parameters being withintheir respective threshold ranges, the method 800 continues at operation830 and the data module 250 stores a data pair that includeslongitudinal acceleration of the vehicle and a drive force for thevehicle.

In one embodiment, the data module 250 determines the drive force basedon a calibration polynomial for each velocity of the vehicle asdescribed in paragraphs 104-109. For example, the calibration module 270may have generated a polynomial for the drive force line of the vehiclewhen traveling at 10 kilometers per hour (KPH). In response to thevehicle currently traveling at 10 KPH, the weight module 230 solves thepolynomial for the drive force.

The method 800 continues at operation 840 and the data module 250determines whether a threshold number of data pairs have been stored. Inresponse to the number of data pairs being stored being below athreshold value, the method 800 continues at operation 810.

In response to the number of data pairs being stored exceeding thethreshold value, the method 800 continues at operation 850 and theweight module 230 performs linear regression analysis on the data pairs.In response to the linear regression error not being below an errorthreshold value (e.g. 0.05), the method 800 continues at operation 850and the weight module 230 continues the linear regression algorithm.

In response to the error being below the threshold error value, themethod continues at operation 870 and the weight module 230 solves thepolynomial resulting from the linear regression analysis for the totalweight of the vehicle and weight being hauled by the vehicle.

FIG. 9 is a flow diagram illustrating one example embodiment of anothermethod 900 for determining total weight, according to one exampleembodiment. Operations in the method 900 may be performed by theautonomous control system 150, using modules described above withrespect to FIGS. 5 and 6. As shown in FIG. 9, the method 900 includesoperations 910, 920, 930, 940, 950, 960 and 970.

In one embodiment, the method 900 begins and at operation 910, theperformance module 240 determines that one or more vehicle performanceparameters fall within respective threshold ranges. The method 900continues at operation 920 and the data module 250 stores a plurality ofdata pairs. The method 900 continues at operation 930 and the weightmodule 230 determines a slope of a line that linearly approximates theplurality of data pairs. In one embodiment, the slope of the linerepresents a total weight that includes the weight of the vehicle andthe weight being hauled by the vehicle. The method 900 continues atoperation 940 and the weight module 230 determines the weight beinghauled by the vehicle by subtracting the weight of the vehicle from thevalue representing the slope of the line. The method continues atoperation 950 and the brake gain value is determined. The method 900continues at operation 960 and the vehicle's operation is modified asrequired.

FIG. 10 is a flow diagram illustrating one example embodiment of amethod for generating calibration polynomials that determine totalweight, according to one example embodiment. Operations in the method1000 may be performed by the autonomous control system 150, usingmodules described above with respect to FIGS. 5 and 6. As shown in FIG.10, the method 1000 includes operations 1010, 1020, 1030, 1040, 1050,1060, 1070, and 1080. In this example embodiment, the calibration module270 generates calibration polynomials for each velocity of the vehicleas described in paragraphs 104-109. As one skilled in the art mayappreciate, such calibration operations are to be done when the vehicleis not currently hauling a weight.

In one embodiment of the method 1000, the method 1000 begins and atoperation 1010, the interface module 220 retrieves a set of vehicleperformance parameters as described at least in paragraphs 67-70. In oneexample, the interface module 220 retrieves a parameter from aninterface for the vehicle and from one or more accelerometers includedas part of the autonomous control system 150.

The method 1000 continues at operation 1020 and the performance module240 determines whether each of a set of vehicle performance parametersare within respective threshold values as described in paragraph 72through 79. In response to any of the vehicle performance parameters notbeing within their respective threshold ranges, the method 1000continues at operation 1010.

In response to each of the vehicle performance parameters being withintheir respective threshold ranges, the method 1000 continues atoperation 1030 and the calibration module 270 calculates a calibrationdrive force and an engine speed. In one example, the calibration module270 determines drive force based on a known weight for the vehicle, anddetermine a drive force by multiplying the weight of the vehicle withthe measured acceleration. The method 1000 continues at operation 1040and the calibration module 270 determines a current velocity for thevehicle and stores the calibration drive force and the engine speed as adata pair in a table for the current velocity.

In one example, the calibration module 270 maintains velocity tables foreach integer velocity of the vehicle between 3 and 25 miles per hour(MPH). In this example, in response to a current velocity of the vehiclebeing 18 MPH, the calibration module 270 stores the data pair in thetable for 18 MPH. Over time, as many data pairs are stored, eachvelocity table includes many data pairs.

The method 1000 continues at operation 1060 and the calibration module270 performs quadratic regression analysis on each of the velocitytables resulting in a second order polynomial for each velocity of thevehicle. In another example embodiment, the weight module 230 determinesa current drive force for the vehicle based on the calibrationpolynomial for a current velocity of the vehicle.

The method 1000 continues at operation 1070 and the calibration module270 determines whether an error for each polynomial as compared with theassociated set of data points is below a threshold error value. XX inresponse to any of the polynomials not satisfying the error thresholdvalue, the calibration module 270 continues regression analysis. Inresponse to each of the polynomials satisfying the error thresholdvalue, the method 1000 continues at operation 1080 and the calibrationmodule 270 stores the coefficients for the polynomials.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A method comprising: a first step of supplying predeterminedcalibration settings relating drive force to motor speed for a vehicletravelling at various speeds; supplying accelerometer data to determinevehicle velocity, acceleration, and direction of travel; supplyingsensors sensing motor performance characteristics; supplying vehiclepitch measurements, roll measurements or a combination thereof;determining filtered data based on the combination of pitch and rollmeasurements; providing accelerometer data to determine vehiclevelocity, acceleration and direction of travel; altering theaccelerometer data based on the filtered data; determining by use of oneor more processors, that one or more vehicle performance parameters fallwithin threshold ranges; determining a weight of a vehicle, a trailerweight, and a total weight of combined vehicle and trailer weights basedon the predetermined calibration settings, accelerometer data and thevehicle performance parameters being within threshold ranges for a firsttime period; determining a first feed forward parameter of the totalweight and delta pitch for the first time period; determining a revisedtotal weight of combined vehicle and trailer weights based on the firstfeed forward parameter, predetermined calibration settings,accelerometer data and the vehicle performance parameters being withinthreshold ranges for a second time period; determining a second feedforward parameter of the revised total weight and delta pitch for thesecond time period; transmitting the second feed forward parameter tothe vehicle's autonomous control system; and controlling the vehicleaccording to revised parameters incorporating the second feed forwardparameter.
 2. The method of claim 1, wherein the determining a vehicleweight further comprises: storing, in response to the vehicleperformance parameters being within the threshold ranges, a plurality ofdata pairs, each data pair comprising a longitudinal acceleration and adrive force, the drive force determined according to a calibratedpolynomial for a current velocity of the vehicle; determining a slope ofa line that linearly approximates the plurality of data pairs, the slopeindicating a total weight, the total weight comprising a weight of thevehicle and a trailer weight; wherein the determining the slope of theline comprises: setting the initial y intercept of force vs.acceleration to zero; and performing regression analysis on theplurality of data pairs resulting in a first order drive forcepolynomial, a first order coefficient representing the total weight. 3.The method of claim 1, wherein the drive force comprises a combineddrive force of all motor drive forces, engine drive forces and motiveforce devices; and wherein supplying predetermined calibration settingsfurther consists of relating motor drive force to motor speed for thevehicle traveling at various speeds.
 4. The method of claim 1, whereinthe vehicle performance parameters are selected from the groupconsisting of lateral acceleration, velocity, electric motor speed,electric motor operating in braking mode as a generator, engine speed,longitudinal acceleration, brakes not being applied, and a transmissiongear ratio.
 5. The method of claim 1, further comprising retrieving oneor more of the vehicle performance parameters from a computing devicefor the vehicle.
 6. The method of claim 3, wherein the combined driveforce is determined by determining a polynomial for each integervelocity of the vehicle by performing regression analysis on calibrationdata pairs for each integer velocity of the vehicle, the calibrationdata pairs comprising a calibration drive force, an electric motor speedand an engine speed, the calibration drive force determined bymultiplying the weight of the vehicle with a longitudinal accelerationof the vehicle when the data pair was recorded.
 7. The method of claim1, wherein the motor is a motive force device comprising one or moreelectric motors, internal combustion engines, and external combustionengines.
 8. The method of claim 1, wherein the autonomous control systemcomprises one or more of the following: a semi-autonomous controlsystem; a fully autonomous control system; adaptive cruise; cruisecontrol; self-driving; and lane centering.
 9. The method of claim 1,wherein the vehicle transmits information about the vehicle's weight andresponse to road conditions based on the weight to one or more separatevehicle's similar autonomous control system.
 10. The method of claim 1,wherein the vehicle receives information from the one or more separatevehicle's similar autonomous control system.
 11. The method of claim 10,wherein the vehicle's autonomous control system modifies control of thevehicle according to revised parameters based on the receivedinformation from the one or more separate vehicle's similar autonomouscontrol systems.
 12. The method of claim 11, wherein modified control ofthe vehicle comprises: controlling the braking of the vehicle;controlling the steering of the vehicle; and controlling theacceleration of the vehicle.
 14. The method of claim 1, wherein thecontrolling the vehicle comprises: controlling the braking of thevehicle; controlling the steering of the vehicle; and controlling theacceleration of the vehicle.
 15. A system comprising: a vehiclecomprising one or more motors; one or more accelerometers that senseacceleration of the system; one or more processors; a drive force modulethat determines a combined drive force of one or more electric motors,engines and motive force devices; a vehicle pitch and roll module thatdetermines filtered data based on the vehicle pitch, roll or both, andaltering accelerometer data based on the filtered data; an interfacemodule that retrieves one or more vehicle performance parameters; aperformance module that determines whether the vehicle performanceparameters fall within respective threshold ranges; a data module thatstores, in response to the vehicle performance parameters being withinthe respective threshold ranges, a plurality of data pairs, each datapair comprising the longitudinal acceleration of the vehicle and a driveforce for the vehicle, the drive force determined according to acalibrated polynomial for a current velocity of the vehicle; a weightmodule that determines a first weight being hauled by the vehicle bydetermining a slope of a line that linearly approximates the pluralityof data pairs, the slope of the line indicating a total weight, thetotal weight comprising a weight of the vehicle and a weight beinghauled by the vehicle for a first time period; the weight module furtherdetermines a weight feed forward parameter of the first weight and deltapitch for the first time period; the weight module further determines asecond weight being hauled by the vehicle for a second time period; theweight module further determines a revised weight based on the weightfeed forward parameter and the second weight an output module thattransmits the revised weight of the vehicle to the autonomous controlsystem; an operation module that modifies operation instructions of theautonomous control system of the vehicle; and a control module thatcontrols the vehicle based on the modified operation instructions. 16.The system of claim 15, further comprising a detection module thatrecords and compares the combined drive force RPM to vehicle speed, anduses this ratio to determine the vehicle's axle ratio and tire size,which is then used to correct the calculated mass.
 17. The method ofclaim 15, wherein the vehicle transmits information about the vehicle'sweight and response to road conditions to one or more separate vehicle'sautonomous control system; and wherein the vehicle receives informationfrom the one or more separate vehicle's autonomous control system andmodifies control of the vehicle according to revised parameters based onthe received information from the one or more separate vehicle'sautonomous control systems.
 18. The method of claim 17, wherein themodified control of the vehicle comprises: controlling the braking ofthe vehicle; controlling the steering of the vehicle; and controllingthe acceleration of the vehicle.
 19. The system of claim 15, furthercomprising a calibration module that determines a polynomial for eachinteger velocity of the vehicle by performing regression analysis oncalibration data pairs for each integer velocity of the vehicle, thecalibration data pairs comprising a calibration drive force and anengine speed, the calibration drive force determined by multiplying theweight of the vehicle with a longitudinal acceleration of the vehiclewhen the data pair was received, the longitudinal acceleration includingthe force of gravity, the data module determining the drive force usingthe polynomial for a current speed of the vehicle.
 20. The system ofclaim 15, wherein the one or more motors comprise one or more electricmotors, internal combustion engines, and external combustion engines.